[CVE-2026-72045][MODERATE 7.0] octeontx2-af: cn10k: restrict VF LMTLINE sharing to its own PF [ Upstream

[CVE-2026-72045][MODERATE 7.0] octeontx2-af: cn10k: restrict VF LMTLINE sharing to its own PF [ Upstream

[AL-KERNEL]

CVE: CVE-2026-72045
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: YES
Patch: octeontx2-af: cn10k: restrict VF LMTLINE sharing to its own PF [ Upstream
Commit: e9c5b03208507dd6d58b0c23a2c60b5c2f4c1b11
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=e9c5b03208507dd6d58b0c23a2c60b5c2f4c1b11
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72045
Analysis date: Sat, 15 Aug 2026 10:39:34 -0400
ActionableScore: 7
ActionableScore lower bound: 5
Actionable bucket: Strong Important candidate / Actionable Moderate at minimum
Manual review required: YES

Summary:
A VF-controlled `base_pcifunc` was not validated against the caller's own PF, allowing cross-function LMTLINE mapping and a potential SR-IOV isolation bypass with confidentiality, integrity, and availability impact on device resources.

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ABOUT THIS REPORT
======================================================================

The original Linux kernel CVE announcement for CVE-2026-72045 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72045

The original announcement does not normally provide a security severity
estimate, CVSS assessment, or enough information to determine whether the
reported kernel bug represents a practically relevant security issue.

This report was generated by AL-KERNEL, an AI-assisted Linux kernel
vulnerability analysis system developed by Alexander Larkin. It combines
an autonomous classifier with LLM-assisted technical analysis and a
separate ActionableScore mechanism.

The purpose of this report is to prioritize Linux kernel CVEs before
manual review, identify cases that require prompt investigation, and
support automatic closure of issues that are unlikely to have meaningful
security impact.

Published priority for this report: MODERATE 7.0
Manual review required: YES

A detailed explanation of the methodology and priority rules is included
at the end of this message.

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AL-KERNEL CLASSIFICATION RESULT
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CVE-2026-72045	MODERATE	CHECK WITH IMPACT FROM ORIG NN IMPORTANT	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H';CWE-862;CWE-284;CWE-269;Other CVSS 'AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L';BEST CVSS score: '8.8';DESCR 'A VF supplied base_pcifunc can be used to select another functions LMTLINE physical base address and copy it into the callers own LMT map entry. This breaks PF and VF isolation because the mailbox source pcifunc is authenticated, but the separate payload field base_pcifunc was not restricted to the callers own PF. For the CVSS the PR:L is used because a local tenant or guest controlled VF can send the mailbox request without host administrator privileges, although triggering requires access to the assigned VF and its driver path. The issue is not network reachable and requires local device or guest access. Impact is a cross function isolation bypass with possible confidentiality, integrity, and availability impact on device resources. For the paranoid score, this is treated as a high impact VF to PF or cross PF isolation risk supported by the LMTLINE physical base sharing context, not as generic kernel memory corruption.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Strong Important candidate / Actionable Moderate at minimum (with actual score 7)	YES	REMOTE OOB SIMPLEFIX NETWORK LINUS KPANIC  DECREASED_TO_MODERATE7_BASED_ON_FALSEPOSCHECKOFKP	YES	NO	checked

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ACTIONABLESCORE ANALYSIS
======================================================================

ActionableScore=7
ActionableScoreLower=5

## 1. ActionableScore

* Conservative score: 5
* Paranoid score: 7
* Final recommended bucket: **Strong Important candidate / Actionable Moderate at minimum**::

## 2. Signal breakdown

Conservative signals:

* Local unprivileged trigger: +1
  A tenant or guest with access to an assigned VF can plausibly issue the mailbox request without host administrator privileges.

* Security-boundary bypass with practical sensitive-object access: +2
  The VF-controlled `base_pcifunc` can select another function's LMTLINE physical base and copy it into the caller's LMT map entry, bypassing intended PF/VF isolation.

* Cross-boundary isolation/policy bypass: +1
  The fix explicitly confines VF callers to their own PF, meaning the original behavior crossed a hardware virtualization boundary.

* Confidentiality impact plausible: +1
  Cross-function LMTLINE mapping may expose another function's device resource layout or transaction region.

* Integrity impact plausible: +1
  A VF may redirect its LMTLINE mapping toward another PF or VF resource, potentially influencing device-side operations outside its allowed scope.

* Availability impact plausible: +1
  Incorrect cross-function LMTLINE sharing may disrupt another function or device operation.

* Rare hardware/configuration dependency: -2
  This requires Marvell OcteonTX2/CN10K AF hardware, SR-IOV style VF usage, and the affected LMTST configuration path.

Paranoid additional signals:

* Practical exploit chain strongly implied: +1
  The chain is direct: VF payload field -> unchecked `base_pcifunc` -> foreign LMT map table index -> caller receives another function's LMTLINE base.

* Privileged device-management / DMA-adjacent state corruption path: +1
  The bug modifies privileged AF-managed device mapping state for LMTLINE regions, which are hardware transaction resources, even though generic kernel memory corruption is not shown.

## 3. Reachability analysis

The bug is not network reachable. It requires local device access, most realistically from a guest or tenant controlling a VF. This should not be treated as PR:H in practical triage because the attacker does not need full host root if a VF is assigned to them.

Namespaces are less relevant than device assignment and SR-IOV isolation. A container without VF access likely cannot trigger it, but a VM or reduced-privilege tenant with a passed-through VF may be in scope.

The path is hardware and configuration specific, so exposure is not broad. However, where deployed, the affected boundary is important because PF/VF and cross-PF isolation are security boundaries.

## 4. Severity interpretation

This is not a generic kernel memory corruption bug. The patch shows an access-control and isolation validation failure in a privileged device-management path.

Realistic impact is at least Actionable Moderate because a VF can influence LMTLINE mapping outside its own PF. The paranoid interpretation reaches Strong Important candidate because the affected object is a physical device transaction region and the bug crosses PF/VF isolation, which may affect confidentiality, integrity, and availability of other device functions.

## 5. One-sentence report phrase

A VF-controlled `base_pcifunc` was not validated against the caller's own PF, allowing cross-function LMTLINE mapping and a potential SR-IOV isolation bypass with confidentiality, integrity, and availability impact on device resources.

## 6. Manual review recommendation

MANUAL CHECK REQUIRED

This should be manually reviewed because it is a hardware virtualization isolation bypass involving VF to PF or cross-PF resource mapping, and the real impact depends on CN10K LMTLINE semantics and how assigned VFs are exposed in the product.

======================================================================
UPSTREAM PATCH SUMMARY
======================================================================

Patch: octeontx2-af: cn10k: restrict VF LMTLINE sharing to its own PF [ Upstream
Commit: e9c5b03208507dd6d58b0c23a2c60b5c2f4c1b11
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=e9c5b03208507dd6d58b0c23a2c60b5c2f4c1b11

Changed files:
  drivers/net/ethernet/marvell/octeontx2/af/rvu.c
  drivers/net/ethernet/marvell/octeontx2/af/rvu.h
  drivers/net/ethernet/marvell/octeontx2/af/rvu_cn10k.c

Diff excerpt:

Not included in this email. See the upstream URL for the full patch.

Full patch:
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=e9c5b03208507dd6d58b0c23a2c60b5c2f4c1b11

======================================================================
DETAILED REPORT METHODOLOGY
======================================================================

The original Linux kernel CVE announcement for CVE-2026-72045 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72045

The original CVE announcement normally does not include a security-level
estimate. In particular, it may not contain a CVSS assessment, an impact
level, or enough information to determine whether the reported bug is a
practically relevant security issue. One purpose of this parallel CVE list
is to provide that missing technical and prioritization information.

The original goal of the AL-KERNEL project was to prioritize Linux kernel
CVE analysis automatically before manual review. The system can also help
identify non-security issues that may be suitable for automatic closure.

This report was generated by AL-KERNEL, an AI-assisted Linux kernel
vulnerability analysis system developed by Alexander Larkin.

The first analysis stage combines an autonomous classifier with additional
LLM-based analysis. The autonomous classifier runs locally on a CPU and is
based on a backpropagation neural network. Together, these mechanisms
produce a technical vulnerability description, identify likely weakness
types, estimate CVSS severity, and provide input for ActionableScore.

Two CVSS estimates are retained because incomplete kernel vulnerability
information often permits more than one defensible interpretation:

  Conservative CVSS vector: AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L
  The Best / paranoid CVSS vector: AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
  The Best / paranoid CVSS score: 8.8

The conservative vector represents a lower-impact interpretation.
The Best/paranoid vector intentionally represents a plausible upper-bound
interpretation and should not automatically be treated as demonstrated
real-world impact.

CVSS may also need to be adjusted for a particular Linux deployment,
because actual reachability, privileges, enabled kernel configuration,
hardware, namespaces, exposed device nodes, and other environmental
conditions can differ significantly between systems.

A separate ActionableScore mechanism evaluates practical remediation
urgency. Its analysis may include reachability, attack prerequisites,
subsystem exposure, memory-corruption characteristics, denial-of-service
reliability, and possible confidentiality, integrity, or
privilege-escalation impact.

  Conservative ActionableScore: 5
  Paranoid ActionableScore: 7

The final base severity is taken directly from the second tab-separated
field of the AL-KERNEL classification result. ActionableScore does not
replace or independently override that final AL-KERNEL decision, and
if ActionableScore adjusted impact level of ALKERNEL, then you would see
self-readable flags above like INCREASED_TO_HIGH_BASED_ON_ACTIONABLESCOREHIGHEREQTHAN7.

For an AL-KERNEL result of MODERATE, this report uses the following
additional presentation split:

  ActionableScore below 5   -> MODERATE REGULAR
  ActionableScore 5 or more -> MODERATE 7.0

The distinction between MODERATE REGULAR and MODERATE 7.0 makes it
possible to identify Moderate issues that should receive manual analysis
and fixes before lower-priority MODERATE REGULAR issues. In many cases,
MODERATE REGULAR fixes may wait for a later rebase or routine update.

There is one override in which MODERATE REGULAR becomes MODERATE 7.0
even when the ActionableScore is below 5. When the AL-KERNEL result
contains the KPANIC flag, a MODERATE result is always presented as
MODERATE 7.0. The KPANIC flag selected with few regexps without
usage of AI at all, so it helps to detect cases when Kernel Crash happens
and similar (to filter False-Negative results from the LLM usage).

KPANIC indicates that a reliable kernel crash, kernel panic, or similarly
serious kernel availability impact was identified by the classification
workflow.

AL-KERNEL base severity for this report: MODERATE
KPANIC detected for this report: YES
Published priority for this report (same as in Subject): MODERATE 7.0

These results are intended to support engineering triage. They are
machine-generated estimates, and cases marked for manual review should
be validated by a human security engineer before final disposition.
For more info read docs linked from here: https://kernelcve.org/
(and you can submit you own patch there to generate such a report
for non-existant CVE-id yet).

Note that in many cases this AI tool selects higher severity, than
real is (means you can expect Importants instead of Moderate 7.0 or
Moderates 7.0 instead of regular Moderates). If you see such cases,
please use reply email interface to add additional manual analyses
info to this particular CVE.
And please, please, let me know when you see Lows instead of Importants
or Important instead of Low (because particular for such cases I
need to tune this AI tool to make it better for this one and next similar).
My contact email for such notifications is alexanjelausa@gmail.com (and both
send reply to CVE record itself too and see "reply" button below for howto reply).